225781354921 has 2 divisors, whose sum is σ = 225781354922. Its totient is φ = 225781354920.

The previous prime is 225781354889. The next prime is 225781354937. The reversal of 225781354921 is 129453187522.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174109245696 + 51672109225 = 417264^2 + 227315^2 .

It is a cyclic number.

It is not a de Polignac number, because 225781354921 - 2⁵ = 225781354889 is a prime.

It is not a weakly prime, because it can be changed into another prime (225781354321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112890677460 + 112890677461.

It is an arithmetic number, because the mean of its divisors is an integer number (112890677461).

Almost surely, 2^225781354921 is an apocalyptic number.

It is an amenable number.

225781354921 is a deficient number, since it is larger than the sum of its proper divisors (1).

225781354921 is an equidigital number, since it uses as much as digits as its factorization.

225781354921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1209600, while the sum is 49.

The spelling of 225781354921 in words is "two hundred twenty-five billion, seven hundred eighty-one million, three hundred fifty-four thousand, nine hundred twenty-one".